Continuous extracting process and apparatus



Sept 23; 1958 K. HEINRICH 2,853,405

CONTINUOUS EXTRAOTING PROCESS AND APPARATUS Filed Jan. 5. 195s 5 sheets-sheet 1 K. HEINRICH CONTINUOUS EXTRACTING PROCESS AND APPARATUS sept. 2,3, 195s 5 sheets-sheet 2 Filed Jan. 5. 1955 Sept. 23, 1958 K. HEINRICH CONTINUOUS EXTRACTING PROCESS AND APPARATUS 5 Sheets-Sheet 3 Filed Jan. 5, 1953 nited Stats Patent CONTINUOUS EXTRACTING PROCESS AND APPARATUS Kurt Heinrich, Grevenbroich, Germany Application January 5, 1953, Serial No. 329,663

Claims priority, application Germany January 3, 1952 7 Claims. (Cl. 127-7) For many years the sugar industry has been looking for a solution to the problem of extracting sugar from sugar beet pulp because the known solution to the probs. lem of manufacturing sugar is dependent on many uncontrollable factors of operation which are tied up with the old battery process. There are already scalding and extracting apparatus which provide a more or less satisfactory solution to this problem. The single or double type extracting towers use more or less worm-shaped stirring members which transport the scalded pulp in counter current to the sugar extracting water. The disadvantage of this system is that it does not transport through the tower an undisturbed layer of pulp, because each worm transports the material supplied thereto at different distances from its axis and at different speeds. The same is true of the known tower systems where the pulp is pumped into the tower through a cone, because here the central pulp layer moves faster than those which move along the walls of the tower.

The different speeds of the pulp result in different extractions therefrom. Since however the quantity of sugar extracting water must be measured according to the fastest moving layer of pulp, in order to avoid too large of a loss of sugar, the amount of extraction water is greater than is the case with a diffusion apparatus where the sugar is extracted from an undisturbed layer of pulp moving only in counter current to the extraction water.

This type of scalding vat is the object of the present invention. Further, extraction in the vat of as much sugar as possible from pulp is required to produce an effective extraction of sugar from the beet pulp. This result can only be accomplished if the pulp in the scalding vat has sugar extracted therefrom according to a certain counter current principle during the scalding stage. In order, however, to bring the temperature of the pulp from a working temperature of approximately 10 C. up to that temperature at which an effective plasmolysis takes place, this temperature -being 70-80 C., without using water at scalding temperature for this purpose, because a part of the pulp would be Vscalded at this temperature, it is necessary to use Ia scalding vat which makes it possible to drive 60G-800% water through the pulp in a direction transverse to the movement thereof, without permitting the finely shredded pulp to stop up the sieve required for the separation.

An extensive extraction of sugar from the lbeet pulp in the scalding vat makes it possible to provide in the tower a high drop of concentration between the water and the pulp so that the diffusion and osmosis is more powerful.

The tower of the present invention is free of built-in parts and provides the advantage, as compared to all known systems which have parts built into the towers, that a low power is required, and also there is a low wear of the parts and low manufacturing costs. Moreover, while all known tower systems of large diameter operate poorly, the tower system of the invention operates practically independently of its diameter because the pulp "ice layers -move through the tower free of worm conveyers which operate poorly just at this location.

The invention will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional view of the scalding vat according to the present invention;

Fig. 2 represents a transverse sectional view of the scalding vat shown in Fig. 1;

Fig. 3 is a sectional view of the extracting tower forming part of the extracting apparatus according to the present invention;

Fig. 4 is a sectional view of the tower as shown in Fig. 3, along line 4-4 of this figure;

Fig. 5 is a section View of the tower as shown in Fig. 3, along line 5-5 of this figure;

Fig. 6 is a sectional view of the tower as shown in Fig. 3, along line 6 6 of this figure;

Fig. 7 is a partial perspective view of the tower as shown in Fig. 3;

Fig. 8 is an enlarged cross sectional view of the distn'butorras shown in Fig. 3; and

Fig. v9 shows the entire extracting apparatus according to the present invention.

In Fig. 1, the section A--B is a longitudinal section wherein the pipe Q carries stirring arms at both of its ends in the regions N and P, whereas the pipe Q is provided with a worm extending through the section O. Thev a uniform, approximately 35% mash. The pulp mash isr engaged by the worm in the region O and is transported through the region O. y

In the region P the pulp mash is engaged by the stirring arms W and goes from the region P to the extraction `tower through a pulp pump which moves the pulp to the extraction tower (shown in Fig. 9).

The extraction tower is illustrated in detail in Figs. 3 to 8. As shown in Fig. 3, a cylinder a forms the outer housing of the tower. A turnable central pipe b drives the pulp distributor d (shown also in Fig. 7) and the pulp ejector i. The cylindrical outer part a of the tower is closed at its bottom end through a conical lower part f. At the boundary surface between the cylinder a and cone f there is a sieve e having long slits. A second sieve n limits the topmost height to which the pulp can rise in the tower due tothe specific weight of the pulp, in its extracted condition, floating in the water. The ejector i which is shown in section 4-4 in plan view (shown in Fig. 4), cuts a corresponding layer out of the rising column of pulp and throws this layer through the opening m to a pulpconveyer l which raises the pulp above the Iwater level in the tower and throws it out at q. The function of the pulp distributor d (shown in Fig. 7) is the following: As a result of the turning of the inner pipe b the distributor d slides slowly, and in a circular motion over the sieve e. The forward part of a distributor d similar to an airplane wing is shown in section in Fig. 8 and includes steel springs which carry a scraper 4 made, for example, of beech wood, this scraper 4 on one side raising the beet mash located thereover and on its other side cleaning the sieve e. The beet mash slides, while being mechanically raised, over and beyond the distributor d and would wall back onto the sieve e whenv the pulp pump stopped operating. This result is prevented, however, by the pulp mash which is pumped through the pipe c to the distributor d. The pressure of the pulp pump is regulated by a speed or pressure regua lator in such a way that the pressure of the pulp mash at the distributor d is somewhat higher'than the static pressure of the pulp column which would fall back onto the sieve e in the free space behind the distributor d. As a result of the turning of the pulp distributor d and as a result of the continuous pumping o f fresh beet mash, a uniform layer of pulp is applied to the top. Sid@ Cf the sieve e beneath the pulp in thev tower. This. process takes place therefore in a hydrornechanical manner. Since. the passive pulp column inA the toweris made, up of a matted mass of b eet pulp, the, staticl overpressure of the pulp pump at the distributor never becomes ofv a critical value. The pulp mashA in the tower may. contain approximately 55 kilograms of beets per hundred liters. A corresponding 35%V pulp mash is pumped tothe distributor. The excess water travels with, the extracted juice through the sieve e out of the tower from where it moves through the conduitv s` into the, counter pressure compensator y, which allows it to overflow intothe conduit J through the overflow Z. Thev counter pressure is adjusted by the height of the overflow which may be changed through a threaded spindle having` a, hand wheel for turning the same.

The extractionof-sugar from the oldest (topmost) pulp layer is brought about by leading a condensate to this oldest layer. through the pipe. k provided with a distributor. The space over the sieve'ny in the tower is heated by vapors of low value. The top, of the tower communicates with the outer atmosphere through the pipe u. ln this way, the. formation of froth in the. tower is avoided.

Pressure water free of pulp Vis supplied through the pipe gV and a distributor h. The distributor h is shown in section 5 in plan view in Fig. 5 and. is provided with pipes. having a streamline` shape so as to. ofer as little resistance as possible to the passing pulp column. Beneath the distributor h there is. provided astirring arm V- which breaks up the matted pulp layer in order to ease the passage` of the pulp layer through the pressure water distributor `h and also' in order to provide an intimate mixing between the pressure water, added sugarcontaining condensate and pulp.

The mash guiding rear part of the distributor d is provided with a wall 7 which is approximately in the form ofv a quarter of aV circle and which tangentially guidesl the mash to the outer wall of the tower. `Also, the distributor is provided with a separating wall at its lower side which separates the mash holding space 6, during distribution from`the sieve e. The form of this separating wall makes it possible to compensate for any irregularity in4 the pfulpjlayer which is. pushedV out. In order to check proper operation carrot pulp maybe inserted into the white pulp yat the vat end. If the separatingwall is correctly shaped, this carrot pulp must arrive at the top of the tower as a closed layer. The shorter the time that the separating plate contacts the mash in the distributor, the more water it loses before it leaves the distributor through the sieve and.v it therefore becomes more concentrated and theA pulp ring rises more quickly up into the tower.

The juice leaving the tower goes together `with the supplied mash juice of the pumped pulp through the sieve e into the conical lower part of the tower. Through,

ring-shaped concentric plates this juice is distributed into zones `whose flow to the outlet pipe s maybe regulated.

from the outside so that in this way the extractionof sugar from all of the pulp inthe tower is also regulated. This is not shown inA the drawings. Nodrypulp is lo-v cated in the tower, instead there is always a mixture of water and pulp floating in the extracted juice. Sugar containing pulp is only slightly heavier thanlwater and pulp of very low sugar'content is somewhat lighter water.

This pulp is stopped bythe sieven fromrising any higher than this sieve. The compensator y regulates the drawing. off of juice by regulatingthe cpunter pressure, The drawn off juice flows through the pipe j into` thel reamrostpart P of the vat (shown in Fig. 1) where is presses the juice of high sugar content in the scalding vat from the pulp mash and in part returns to. theA tower together with the pulp mash. The overflowing part of the drawn off juice, however, travels to the pipe H of the vat which draws olf the juice therefrom through pipe K. An upwardly directed pipe E communicating with the outer atmosphere permits all air to leave the vat so that a mash free of air is supplied to the distributor d of the tower. See Figs. l and 9.

The drawing olf pipe H (shown in Fig. 1) extends along the entire length of the vat. It is hollow in its interior and has a partition R which divides the pipe H into sections H1 and H2. Section H2 gathers the raw juice from the freshly shredded pulp in the mash in section N, while section H1 takes up all of the circulating juice of the vat which travels transversely through the vat in a quantity of about 600-800% of the pulp. The circulating juice travels through the pipe L from the section H1 to the circulating pump which. moves it through a heater and partly through the pipe D, connected to the vat at an intermediate portion thereof, again into the pulp mash at a temperature which produces plasmolysis of the pulp without scalding it. However, a part of the circulating juice is driven by the circulating pump through a second heater and along the conduit I (as shown in Fig. 2) to wash the freshlycut pulp into the vat. This juice delivered to conduit J from the second heater may, have a temperature of over. C. since it is cooled by the cold freshly cut pulp and enters the apparatus at a temperature of about 45 C. The juice drawing pipe H; turns. at a moderate speed in the pulp mash and is continually. cleaned by the. scrapers U. The scrapers U are pressed lightly against the tubular sieve H either by weights X mounted on the scrapers U or through suitable springs. In the region O of the vat there are provided stop members F which serve the` purpose-of preventing rotation of the pulp in the region of the worm screw. If the members F together with the stream of juice moving towardthe pipe H do not suffice, then a known stop means may be provided to accomplish this result, such a known stop means extending into the worm region which would thenbe interrupted. It is also possible, however, to produce this result with the stationary worm floor in which the pipe Q turns because the pulp mash moves through the pulp pump with an initial pressure produced in the pipe C and following along the worm screw. The control of the installation can be carried out according to the density of juice in the conduit j, according to the.V current used in driving the vat as a measure of mash density, according to the speed of rotation of the pump distributor drive and according to the speed of rotation of thepulppump. It is further possible to omit a drive to the pulp distributor d through P (shown in Fig. 3), because the reaction pressureof the pulp mash on the rear side of the distributor and opposed to the mash column provides a considerable turning moment. The resistance of the forward side of the distributor is very low because the scraper 4 slides very close to the sieve e and can easily raisel the floating pulp.

The emptying of the contents of the tower therefrom after. extraction of sugar is very easily carried'out through the movablecover t, while the distributor isl so located with respect to the opening covered by cover t that with suitable water itsprays theV pulp out of the tower into a suitablersump or pulp pump.

It is also possible to supply pulp to the tower through the inner pipe b thereof and do away with a stuffing boxr forthe pipe c, if the pulp pump is controlled by a float valve in the center pipe and if the required maximum overI pressure of the pulp column in the central pipeV b. isvknown, so. that a satisfactory supplyv of pulp. to the` It is also possible to of the extraction apparatus will eliminate the need for a special vat. inasmuch as the tower can be made of any size because it is free from screw shaped stirring arms, the vat will be arranged upright within a sufficiently great pipe in which case the latter is made stationary with the vat housing. Then only the vatshaft would rotate, and this latter shaft would simultaneously drive the distributor. The ejector and juice drawing pipe of the vat would then have a special drive.

I claim:

l. A process for extracting juices from fruits or vegetables, comprising the steps of moving pulp of the material from which juice is to be extracted through a closed heating vat by means of a rotating worm located in the vat; maintaining the spaces between the thread turns of the worm substantially filled with said pulp; simultaneously introducing a liquid having some extracted juice dissolved therein into a first part of the vat; moving the thus introduced liquid through the pulp transversely to the direction of movement thereof and through a sieve into a chamber formed by the sieve, extending along the length of the vat, and being separated therefrom by the sieve so that the liquid carries away and is enriched by juices from the pulp; drawing the thus enriched liquid from the chamber formed by the sieve;

heatingthe thus drawn liquid; Vcontinuously returning a portion of the thus heated liquid to a second part of the vat spaced from the first part thereof; again heating the remainder of the thus drawn liquid; conveying the thus heated remainder of the liquid into the vat together with a quantity of fresh pulp; moving the thus conveyed liquid transversely through the pulp and sieve into a portion of the chamber separated from the remainder thereof to further enrich the liquid with additional juices from the fresh pulp; and removing the liquid from the separated chamber portion.

2. In a heating vat for heating the pulp of fruits or vegetables to the state of plasmolysis and for extracting juices from a pulp mash, in combination, an elongated, horizontally extending, closed vat housing; an elongated worm having a shaft extending horizontally in said vat housing and being turnable therein; an inlet communicating with one end of said vat housing for supplying a fresh pulp mash to said worm to be moved by the latter to the opposite end of said vat housing; an outlet connected to said opposite end of said vat housing for conveying the pulp mash from the latter; a cylindrical sieve extending along the length of said vat housing in the interior thereof and adjacent an upper portion thereof; scraper means operatively connected to said sieve for cleaning the same; partition means located in said sieve for dividing the same into a least two chambers one of which is located adjacent said one end of said vat housing and the other of which extends from said partition means to said opposite end of said vat housing; pump means connected to said other chamber for drawing liquid therefrom; first conduit means leading from said pump means to an intermediate portion of said vat housing for conveying liquid from said pump means back into said vat housing; second conduit means leading to a portion of the vat housing adjacent said opposite end thereof for supplying liquid to the interior thereof to pass to said other chamber and be drawn by said pump means into said first conduit means; third conduit means leading from said pump means to said inlet of said vat housing for supplying liquid thereto; and duct means leading from said one chamber to convey raw juice therefrom.

3. In a heating vat for heating the pulp of fruits r vegetables to the state of plasmolysis and for extracting juices from a pulp mash, in combination, an elongated, horizontally extending, closed vat housing; an elongated worm having a shaft extending horizontally in said vat housing and being turnable therein; an inlet communicating with one end of said vat housing for supplying a fresh pulp mash to said Worm to be moved by the latter to the opposite end of said vat housing; an outlet connected to said opposite end of said vat housing for conveying the pulp mash from the latter; a cylindrical sieve extending along the length of said vat housing in the interior thereof and adjacent an upper portion thereof; scraper means operatively connected to said sieve for cleaning the same; partition means located in said sieve for `dividing the same into at least two chambers one of which is located adjacent said one end of said vat housing and the other of which extends from said partition means .to said opposite end of said vat housing; pump means connected to said other chamber for drawing liquid therefrom; first conduit means leading from said pump means to an intermediate portion of said vat housing for conveying liquid from said pump means back into said vat housing; second conduit means leading to a portion of the vat housing adjacent said opposite end thereof for supplying liquid to the interior thereof to pass to said other chamber and be drawn by said pump means into said first conduitmeaus; third conduit means leading from said pump means to said inlety of said vat housing for supplying liquid thereto; duct means leading from said one chamber to convey raw juice therefrom; and a plurality of stirring arms fixed to said shaft of said worm for rotation therewith and being located at opposite ends of the worm thread.

4. In a heating vat` for heating the pulp of fruits or vegetables to the state of plasmolysis and for extracting juices from a pulp mash, in combination, an elongated, horizontally extending, closed vat housing; an elongated Worm having a shaft extending horizontally in said vat housing and being turntable therein; an inlet communieating with one end ofsaid vat housing for supplying a fresh pulp mash to said worm to be moved by the latter to the opposite end of said vat housing; an outlet connected to said opposite end of said vat housing for conveying the pulp mash from the latter; a cylindrical sieve extending along the length of said vat housing in the interior thereof and adjacent an upper portion thereof;rscraper means operatively connected to said sieve for cleaning the -samel and comprising a plurality of scraper members movably mounted in said vat housing and engaging said sieve, and a plurality of weights respectively mounted on said scraper members to urge the same against said sieve to clean the latter during rotation thereof; partition means located in said sieve for dividing the same into at least two chambers one of which is located adjacent said one end of said Vat housing and the other of which extends from said partition means to said opposite end of said vat housing; pump means connected to said other chamber for drawing liquid therefrom; first conduit means leading from said pump means to an intermediate portion of said vat housing for Conveying liquid from said pump means back into said vat housing; second conduit means leading to a portion of the vat housing adjacent said opposite end thereof for supplying liquid to the interior thereof to pass to said other chamber and be drawn by said pump means into said first conduit means; third conduit means leading from said pump means to said inlet of said vat housing for supplying liquid thereto; and duct means leading from said one chamber to convey raw juice therefrom.

5. In a heating vat for heating the pulp of fruits or vegetables to the state of plasmolysis and for extracting juices from a pulp mash, in combination, an elongated, horizontally extending, closed vat housing; an elongated worm having a shaft extending horizontally in said vat housing and being turnable therein; an inlet communicating with one end of said vat housing for supplying a fresh pulp mash to said worm to be moved by the latter to the opposite end of said vat housing; an outlet connected to said opposite end of said vat housing for conveying the pulp mash from the latter; a cylindrical sieve extending along the length of said vat housing in the interior thereof and adjacent an upper portion thereof; Scraper means. operatively Connected, to Said, Sieve, for.

Cleaning the Same; partition means. located. in; Said Sieve, for dividing the same into at least two, chambers one of thereof Yfor supplying liquid to the interior 'thereof to` pass to said other chamberV and4 be drawn by said pumpv means into said first conduit means; third conduit means leading from said pump means to said inlet of said Vat housing for supplying liquidl thereto; duct means leading from .said one chamben to convey raw juice therefrom; and heater means mounted in said first conduit means for heating a liquid passing therethorugh.

6. `In a heating vat for heating the pulp. of fruits or vegetables to the state of plasmolysis and for extracting juices from =a pulp mash, in combination, an elongated, horizontally extending, closed4 vat housing; an elongated worm having a shaft extending horizontally in said vat housing and -being turnable therein; van inlet communicating with one end of said vat housing for supplying a fresh pulp mash yto said worm to be moved bythe latter to the opposite end of said vat housing; an outlet connected to said opposite end of saidy vat housing for conveying the pulp mash from the latter; a cylindrical sieve extending along the length of said vat housing inthe interior thereof and adjacent an upper portion thereof; scraper means operatively connected to said sieve for cleaningthe same; partition means located in said sieve for dividing the'same into at least two chambers one of which is located ad,-

jacent said one end of said vat housing and the other of which extends from said partition means to said opposite end of said vat housing; pump means connected to, said,

other chamber lfor drawing liquid therefrom; first conduit means leading from said pump means rto an intermediate portion of said vat housing for conveying liquid from said pump means back into saidl vat'housing; second conduit means leading to a portion of the vat housing adjacent said opposite endl -thereof for supplying liquid to the interior thereof to pass to said other chamber and be drawn by said pumpv means into4 said rst conduit means; third conduit means leading from said pump means to said inlet of said vat housing for supplying liquid thereto; duct means leading from` said one chamber to convey raw juice therefrom; lirst heater means mounted in said first conduit means for heating a liquidpassing therethrough; and second heater :means mounted in said third conduit means for heatinga liquid passing therethrough.

7. In a process preliminary to counter-current extraction of juices from fruits and vegetables, the steps of: moving in a given `direction pulp of the material from which juice is to be extracted; moving transversely across the pulp a liquid having some extracted juice dissolved therein, thereby enriching the liquid withV juices from the pulp; drawing the` thus enriched liquid from the pulp;

heating the thus drawn liquid; continuously returning at least a portion of the; thus heated liquid to the pulp; 'again heating the remainder of the thus drawn liquid; conveying the thus heated remainder of the liquid toward the pulp together with a quantity of fresh pulp being moved in said given direction; moving the thus conveyed liquid ltransversely across the fresh pulp, thereby further enriching the liquid with juices lfrom the -fresh pulp; and dlrlzliwing Vthe thus further enriched liquid from the fresh P P- References Citedin the iile of this patent Ul \IIlED,v STATESr PATENTS 706,669 Kessler Aug. 12, 19,02 1,006,311 Steffen Oct. 17, 1911 1,437,801 Graham- Dec. 5, 1922 1,782,603 'Camuset Nov. 25, 1930 2,466,259 Morton Apr. 5, 1949 2,502,939 Frynta 'Apr. 4, 1950 2,548,996 Morton Apr. 17, 1951 2,569,199 Smet Sept. 25, 1951k FOREIGN PATENTS 498,824 Belgium Nov. 14, 1950 

1. A PROCESS FOR EXTRACTING JUICES FROM FRUITS OR VEGETABLES, COMPRISING THE STEPS OF MOVING PULP OF THE MATERIAL FROM WHICH JUICE TO BE EXTRACTED THROUGH A CLOSED HEATING VAT BY MEANS OF A ROTATING WORM LOCATED IN THE VAT; MAINTAINING THE SPACES BETWEEN THNE THREAD TURNS OF THE WORM SUBSTANTIALLY FILLED WITH SAID PUL; SIMULTANWOUSLY INTRODUCING A LIQUID HAVING SOME EXTRACTED JUICE DISSOLVED THEREIN INTO A FIRST PART OF THE VAT; MOVING THE THUS INTRODUCED LIQUID THROUGH THE PULP TRANSVERSELY TO THE DIRECTION OF MOVEMENT THEREOF AND THROUGH A SIEVE INTO A CHAMBER FORMED BY THE SIEVE, EXTENDING ALONG THE LENGTH OF THE VAT, AND BEING SEPARATED THEREFROM BY THE SIEVE SO THAT THE LIQUID CARRIES AWAY AND IS ENRICHED BY JUICES FROM THE PULP; DRAWING THE THUS ENRICHED LIQUID FROM THE CHAMBER FORMED BY THE SIEVE HEATING THE THUS DRAWN LIQUID; CONTINUOUSLY RETURNING A PORTION OF THE THUS HEATED LIQUID TO A SECOND PART OF THE VAT SPACED FROM THE FIRST PART THEREOF; AGAIN HEATING THE REMAINDER OF THE THUS DRAWN LIQUID; CONVEYING THE THUS HEATED REMAINDER OF THE LIQUID INTO THE VAT TOGETHER WITH A QUANTITY OF FRESH PULP; MOVING THE THUS CONVEYED LIQUID TRANSVERSELY THROUGH THE PULP AND SIEVE INTO A PORTION OF THE CHAMBER SEPARATED FROM THE REAMAINDER THEREOF TO FURTHER ENRICH THE LIQUID WITH ADDITIONAL JUICES FROM THE FRESH PULP; AND REMOVING THE LIQUID FROM THE SEPARATED CHAMBER PORTION. 